Figure 1From: Rapid evolution of mammalian X-linked testis microRNAsDensity distribution of miRNAs across chromosomes among species. Densities of miRNAs on the X chromosome and autosomes are shown for different species, except for chicken, where the Z chromosome is used instead of X. Densities are shown as number of miRNAs per megabase of DNA. The ratios of densities between the X chromosome and autosomes are shown in brackets. Mammals in the species tree on the left are shaded in grey.Back to article page